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(No Model.) 2 Sheets-Sheet 1. l W. E. SAWY-ER.

Electrical Safety Device for Elevators.

No. 231,743. Patented Aug. 31,1880.

N. PETERS. PHOTO-UTHOGRAPMER, WASHXNGTON. D c.

r (N d l-I 2 Sheets-Sheet 2.

W E. SAWYER. Electrical Safety Device for Elevatdrs.

No. 231,743. e Patented Aug, 31,1880.

NPETERS. FNOIO-UTHOGMPHER, WASHINGTON. 0 c4 I Unwrap States Parana: @rrren.

WILLIAM E. SAW YER, OF NEW YORK, N. Y.

ELECTRICAL SAFETY DEVICE FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 231,743, dated August 31, 1880.

Application filed July 19, 1880.

To all whom it may concern Be it known that I, WILLIAM E. SAWYER, a citizen of the United States, residing-at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Electric Safety Devices for Elevators; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accoinpanyii'ig drawings, and to letters or figures of'reference marked thereon, which form a part of this specification.

My invention relates to safety devices for elevators such as used in hotels, office-buildings, stores, mines, Ste.

The object of it is to provide means whereby the opening or closing of the door at each landing of the elevator-car will bring into operation suitable electromagnetic locking devices whereby the winding'drum or hoisting apparatus is automatically stopped orlocked and any movement of the car prevented until the door has been opened or closed (according to the circuit being a closed or opened one) at each tloor or landing, thus preventing persons from attempting to en ter or get out of an ascending or descending car through a partiallyclosed door while the car is in motion. It is well known that accidents from such causes are of frequent occurrence. Theattendants or operators of elevator-cars often open the door leading to the car before the car has entirely reached the landing and is still in motion, and passengers commence to get out of or enter the car while in motion, and accidents of a serious nature have occured in this way. 7

The means for automatically stopping the car and accomplishing the several purposes above mentioned will be hereinafter more fully described in the specification and pointed out in the drawings, in which- Figure 1 is a vertical section of an elevator embodying my invention .on a closed-circuit system; Fi 2, the same in an open-circuit system.

A is the outer door of the well or approach to the elevator-car K. ,This door slides past the permanently-fixed frame or door A in the (No model.)

ordinary manner. At the side of the well, and securely-fastened thereto, are two metallic circuitclosers, B B, which are electrically connected with a source of electricity, 0, located at any convenient point, and in the circuit thereofis an electromagnet, D, which operates a lever-armature, f, pivoted at e, and provided with a detent or pawl, 61, adapted to engage with a ratchet-wheel, G, on the shaft of windingdrum F, and acting against the strain or exertive force of a suitable rctractile spring, S, secured at the top or side of the well in any convenient manner.

The several floors or lan din gs are represented at I) b. L represents the ordinary operatingcord, and N the lifting-cord, passing over pulley M.

The circuit-closers in Fig. 2 are pushed apart by a piece, 0, attached to the top of door A.

The several circuits are indicated by figures l, 2, 2", and 3.

The operation of the device is as follows: We will suppose the car to beat the second lioororlanding, b. (See/Fig. 1.) The door being opened, as shown, the metallic spring B is separated from contact-piece B. No current will now flow from the source of electricity G, and consequently the exertive force of spring S acts to hold the detent d of the armature-lever in the ratchet-wheel G. Hence no movement of the starting-rope will operate to start the car; but suppose the attendant closes the outer door, this action forces spring B into metallic contact with contact-piece B and closes the circuit to electro-magnet D, which will then attract the armature E to the ma net and against the strain of spring S, and withdraw the detent cl from the ratchet-wheel, whereupon the attendant is enabled to start the car. This operation is performed at each floor or landing where the door is opened. Now, when the car descends to floor I) and the door is pushed back to allow passengers to depart from or enter the car the spring B is released from contact with contact-piece B, and the circuit is thereby broken, the magnet releases the armature and allows the detent to fall into the ratchet-wheel, and the hoisting mechanismvis again locked until the door is again closed.

In Fig. 2 the movable door A carries on its upper edge a projection, O, which forces back the spring B from the contact-piece B. In this arrangement of the electro-magnet D and the lever f the magnet is placed between the pivot 0 and the detent, so that when the circuit is completed the magnet draws the detent into the ratchet-wheel G and stops the further movement of the car.

One terminal of electro-magnet D is connected by wire 2 to one pole of source of electricity 0. The other pole of Ois connected to the the contact-pieces B ateach landing by wire 3. The other terminal of the magnet is connected to the springs B by the wire 1.

Suppose 011 floor b the car is stopped and the door opened, the spring B makes metallie contact with contact-pieceB. The current now passes by way of wire 1, magnet D, wire 2", source of electricity 0, and wire 3, the armature is attracted, and detent (I forced into contact with wheel G, and further movement of the car arrested until the door A is closed and the projection O is brought against and forces back spring B, thereby breaking the connection between the spring and contactpiece, thus opening the circuit to magnet D, whereupon the spring S withdraws the detent from ratchet-wheel G, and the car can again be started.

Thus it will be seen that it the attendant does not allow the car to arrive at the landing, but opens thegdoor when :several feet above or below the landing, the car will be stopped at that position, so that he must push Y the door to and close the circuit in one instance or open it in the second instance, so as to allow the car to come completely to the landing, thereby preventing the accidents before referred to.

In the open-circuit system, as illustrated in Fig. 2, the circuit is normally broken, so that it any accident should occur to one of the conductors the circuit remains broken and the device still operates. It is obvious that the magnet can be used to release anyother mechanism for locking the drum or hoisting mechanism.

The circuit breakers or closers may be secured to the floors of the landings and the circuit opened or closed by a wheel or strip of metal suitably attached to the door.

Having thus explained the operation of my device and described the invention, What I claim as new is 1. A safety devicet'or elevators automatically controlled by suitable mechanism through the intervention of a generator of electricity having in its circuit a system of circuit closers or breakers operated by the door of the elevator, substantially as described.

2. An elevator the hoisting mechanism of which is automatically locked or released by an armature-lever the movement of which is controlled by a generator of electricity having in its circuit an electro-magnet and a system of circuit closers or breakers operated by the door of the elevator.

3. In an elevator, a car which is automatically stopped or allowed to move by suitable mechanism through the intervention of a gene rator of electricity having in its circuit a system of circuit closers or breakers operated by I the elevator-door, substantially as described.

4. In an elevator, at system of circuit closers or breakers at each floor or landing, having in their circuit an electric safety device connected with the hoisting mechanism of the elevator, said circuit closers or breakers being operated by the elevator-door at each landing or floor, substantially as described, and for the purpose set forth.

5. An elevator the winding-drum of which is automatically locked and released by an armature-lever. said lever being attracted by a magnet in the circuit of an electric generator, and a system of circuit closers or breakcrs operated by the doors of the elevator, substantially as described.

6. In an elevator, the combination of the winding-drum havinga ratchet-wheel attached thereto, an armature-lever provided with a detent engaging with the ratchet-wheel, with the 0 magnet D, battery 0, and circuit opening or closingdevices B B, substantially as described, and for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

WILLIAM EDWARD SAWYER.

Witnesses: I

WM. G. OoNKLrN,

G. G. THATCHER. 

